The presence in Nazi Germany of a large number of various projects of military equipment, unrealized and fantastic, has long been the reason for various speculations. It was the development of the Germans that, to some extent, owe their appearance to the legend of "fu fighters" and other unidentified flying objects. In addition, the legends of German bases in Antarctica also feature unusual disc-shaped aircraft. Despite their obvious nature, all these stories and theories are not just fantasy. There are some reasons for them. In Germany, indeed, work was carried out in the field of aircraft with an unusual wing shape. So, in the search for a way to improve the flight characteristics of traditional aircraft, the Ju-287 bomber with a forward-swept wing was created. In addition, projects for vertical take-off vehicles were created. Finally, the third direction in the development of aviation, German engineers saw a disc-shaped wing or even a complete rejection of this part of the apparatus. Consider German discs, which have been confirmed by more than rumors.
Herr Focke's patent
Back in 1939, Heinrich Focke, the chief designer of Fokke-Wulf, applied for a patent for a new aircraft concept. In the application it was named simply: "an aircraft with a vertical take-off capability." On the surviving drawings by Focke, you can see the approximate layout of this device. Most of the structure is made up of the wing. Its front edge has a parabolic shape, and its rear edge is straight, with a backward sweep. The thickness of the wing profile is quite large and in the central part is comparable to the height of the fuselage. The latter is neatly inscribed in the wing structure. In fact, the Focke aircraft designed for vertical take-off is a flying wing, from which only the teardrop-shaped cockpit in the front and the keel in the rear protrude. But the main design nuance lies in the middle part of the combined wing-fuselage unit.
In the central part of the aircraft there is a round channel of large diameter, passing through the entire thickness of the wing. It houses two coaxial screws rotating in different directions. The propellers were supposed to be driven by motors located at the rear of the apparatus. The gearbox, which ensures the rotation of the screws towards each other, obviously had to be mounted in a common fairing of the screw hubs. As conceived by Focke, the propellers were supposed to work both as lifting and as propulsion devices. In connection with the original propeller group, it is worth considering the control system. Almost along the entire length of the trailing edge of the wing, the vertical takeoff aircraft had elevons for roll and pitch control. The rudder was located on the keel. All in all, nothing special for a tailless plane. However, another original control was directly connected to the propellers. The lower outlet of the screw channel was closed with special flaps. In the parking lot, they were closed, and in flight it was supposed to change their position. This was done in order to change the thrust vector of the propellers. In addition, it should be noted that on the existing diagrams, the screws are not located parallel to the horizontal axis of the apparatus, but inclined forward. Due to this arrangement, they provide vertical thrust in the takeoff and landing position, compensating for the peculiarities of the parking position (three-point chassis with a crutch). After taking off from the ground, the pilot, controlling the shutters of the outlet, had to transfer the apparatus to a horizontal position. In this case, the plane of rotation of the screws turned out to be at an angle to the horizon and further, using the same valves, it was possible to control the thrust vector and flight speed. When landing, accordingly, the pilot had to transfer the aircraft from horizontal flight to hovering mode, bring the pitch angle to the parking value and, smoothly dropping the thrust, make a touchdown and landing.
There is information about the blowing of the models of this apparatus in wind tunnels. In addition, sometimes there are statements about the existence of small models made in accordance with the proposal of G. Focke. After the war, the patent and related documentation fell into the hands of the Allies. The project aroused considerable interest, which subsequently resulted in research on the topic of a parabolic or round wing and vertical take-off vehicles. There is no data on the existence of at least a full-size model of this aircraft. However, the "vertical take-off aircraft" is well known to aviation historians as the Fokke Wulf VTOL (Vertical Take-Off and Landing). It should be noted that the term VTOL comes from the English language. Why is the German project designated for them? The fact is that in the German documentation there is no designation for this aircraft, in addition to the definition of the possibility of vertical takeoff.
From model to plane
In the same year, 1939, the first National Aircraft Modeling Competition was held. Among others, a young farmer Arthur Sak, whose hobby was aviation, offered his aircraft model with an internal combustion engine. His AS-1 aircraft had an unusual wing. The unit with a span of 125 centimeters had a round shape in plan. According to Sack's idea, such a wing layout could provide the aircraft with good values of lift and, as a result, maneuverability, controllability and carrying capacity. The model weighing four and a half kilograms was equipped with a weak gasoline engine. Because of this, the AS-1 was able to fly the test distance of one hundred meters, but its speed made me forget about the prizes. However, in the end, Sak received a more interesting "prize".
The competition was attended by Ernst Udet himself, who by that time had become one of the most important people in the Luftwaffe. He became interested in the original wing of the model and invited Saku to continue work on this topic in more suitable conditions for research. The next years were spent studying the disc wing in wind tunnels, searching for the optimal profile and a lot of other things. Based on the results of these studies, four models with indices from AS-2 to AS-5 were built with a break of several months. They differed from each other in design features, as well as in size. In the fall of 1943, A. Saka's project reached the stage when it was possible to start creating a full-size manned prototype.
For the assembly of the experimental aircraft, Saku was assigned the Flugplatz-Werkstatt workshops at the Brandis airfield, where construction began at the end of 1943. The manned plane with a disc-shaped wing received the designation AS-6. Under the guidance of a former farmer, the workshop workers assembled the original wing. Three spars carried eight ribs each and were attached to the fuselage frame. In addition, an additional load-bearing element was mounted along the edge of the wing, the purpose of which was to ensure the rigidity of the edges of the bearing plane. The wooden wing structure with metal attachments was completely new, which is not the case with other aircraft units. The Argus As-10C-3 gasoline engine (240 hp), along with a part of the engine mount and the hood, was borrowed from the lightweight Messerschmitt Bf-108 Taifun. The landing gear, cockpit, canopy and a number of other parts were removed from the crashed Bf-109B fighter. As for the tail unit, this unit was redesigned, albeit with extensive use of elements of existing aircraft.
AS-6 1944
If we compare the design of the AS-6 with other aircraft of that time, then it is distinguished only by the shape of the wing and its power set. The rest of the Saka plane was similar to many other designs. Unless the dashboard of the AS-6 had a Spartan look - only six instruments. The aircraft was controlled using standard controls for this technique. At the disposal of the pilot were throttle sticks, aircraft controls, and pedals. For pitch control, the stabilizer had an elevator, the pedals were associated with the rudder, and the ailerons of the original form were placed on the trailing edge of the wing.
In February 1944, testing of an experimental aircraft began. They started with jogging. In general, these tests were found satisfactory, although the low efficiency of the rudders caused criticism. In addition, the components removed from the crashed plane were not very reliable, and they constantly had to be repaired. After all the repairs, taxiing was continued. During the second stage of ground checks, it turned out that the reason for the low efficiency of the rudders lies in their location. Due to the original wing design - with a long root part - the rudders ended up in a low pressure zone that followed the planes. In addition, during the last run down the runway, the landing gear fell off the vehicle. Another repair followed, this time a larger one, because the wing was damaged during the "braking".
New calculations showed that the AS-6 owes its failures primarily to a weak engine. A. Saka had no other motors at his disposal, so it was decided to increase the angle of attack. The most obvious way to do this is to move the landing gear struts. But the dense arrangement of power elements and units inside the fuselage did not allow this to be done. Therefore, the alteration of the chassis affected the installation of brakes (taken from the Ju-88 bomber) and the installation of a 70 kg balancing weight on the third spar, as well as additional aerodynamic surfaces on the trailing edge of the wing. Now, according to the calculations of the designers, during the take-off run the plane had to have the desired angle of attack. The improvements made have yielded results. The third series of taxiways demonstrated an increase in the efficiency of the rudders, and the plane was constantly "rushing upward." The first flight was scheduled for the fourth test phase. Pilot G. Baltabol moved the throttle stick all the way forward and began the takeoff run. After taking off, the plane began to roll to the side. The pilot managed to release the throttle and land carefully. The reason for this was simple: the low aspect ratio wing and small area ailerons could not effectively counter the propeller's reactive moment. Since this problem was a direct consequence of the very concept of the AS-6 aircraft, Baltabol refused to continue testing until the appropriate corrections were implemented. The pilot complained most of all about a weak engine and insufficient rudder efficiency. Finally, he advised to work in a wind tunnel for another month or two and only then start flight tests.
Arthur Sak returned to the drawer and the wind tunnel. While he was working on improving the machine, in the summer of 44, the I / JG400 regiment was transferred to the Brandis airfield, the pilots of which flew Me-163 fighters. The pilots of the 400th squadron had good experience in flying heavy-to-fly aircraft, so they were immediately interested in AS-6. It was the combatant pilots who came up with the nickname Bierdeckel - "Beer Tray" for the round-wing aircraft. And one of the pilots even volunteered to conduct a test flight. Lieutenant F. Roslet made a few runs and a small approach. Upon touching the ground, the AS-6 lost its landing gear again, and the disgruntled Roslet left exactly the same recommendations that Baltabol had previously given.
Launching the AS-6 lasted almost until the end of the war. Saku was helped by engineers from several design bureaus, but all this did not have the desired effect. In April 45, an experienced AS-6 was badly damaged during the bombardment of Brandis airfield. When US forces took over the airfield, they did not find any parts or remains of the aircraft. Probably, the wreckage of the car was disassembled and disposed of as unnecessary.
Belontse, Zimmerman and others …
The Fokke-Wulf VTOL and AS-6 projects have one thing in common: their existence is confirmed by documents and photographs (this applies only to the latter). However, other German aircraft, which cannot “boast” of such evidence of their existence, often receive more attention from fans of original aviation technology.
It all started in the 50s, when the book by R. Luzar "The Secret Weapon of the Third Reich" was published in Western countries. It told about some disk-shaped miraculous devices that could take off to an altitude of 12-15 kilometers and accelerate to either two or four thousand kilometers per hour. And they demonstrated all this already in the first flight. It was from this book that the public learned about a fundamentally new "Schauberger engine", which allowed German aircraft, in particular the notorious "Belonza disk", to have such outstanding characteristics. Luzar's book contained diagrams and even muddy, blurry photographs of these "flying saucers". True, there was not a single reference to well-known documents in it. Therefore, "The Secret Weapon of the Third Reich" soon became a favorite publication of various lovers of secrets and riddles.
In the search for "secret developments" in Germany, sometimes it comes to the ridiculous. So, sometimes in the list of German "flying saucers" a certain "Zimmermann's flying pancake" is given. It is said that the German engineer Hans (in some sources Heinrich) Zimmermann, back in 1943, created a disc-shaped aircraft with outstanding characteristics. Various quotes of alleged witnesses who allegedly attended the tests, etc. are given. We have to admit that the "Zimmermann pancake" really existed. Only there are a few "buts". First, Zimmerman's name was Charles. Secondly, he worked for the American firm Chance Vought. Third, the "flying pancakes" were officially named V-173 and XF5U. Finally, Zimmermann's planes, nicknamed "Blin" and "Shumovka", respectively, are widely known to aviation enthusiasts and are not any particular mystery. But that's a completely different story.
